Boat hull



' March 13, 1945.

A. A. STEELE BOAT um.

Filed April 5, 1945 2 Sheets-Sheet l Snventor lll I! March 13, 1945.STEELE I 2,371,478"

BOAT HULL Filed April 5, 1943 ZSheets-Sheet 22 35 I 3nventor: ARCH/E ,4.STEELE.

Patented Mar. 13, 1945 UNITED STATES PATENT OFFICE r 2,371,478 J W pon'rHULL I Archie A. Steele, Los dngeleacalif. Application April 5, 1943,Serial No. 4813319 7 Claims. (01. iii-'62)" My invention relates toboats, and relates in" particular to a combinedsail and motor drivenvessel having relatively high speed under either sail or motor power,and for this reason beingespecially adapted for use as a sub-chaser orcoast patrol vessel.

The usefulness and advantages of a boat of'this character may be readilyperceived from a consideration of a proposed 96-foot ship havingcomfortable accommodations for eighteen men. -A vessel as aboveindicated, rn'ade in accordance with my invention and equipped withsubmarine and atmosphericflistening devices, 40 mm. guns,

and depth bombs, is capable of patrolling an area at a considerabledistance froma base. nary patrol service would be accomplished undersail power at a speed which would have a maximum of about 13 nauticalmiles per hour in a would have an approximate speed of 25 knots, so-

as to be fast enough to catch or escape from a submarine", as the caserequired. Cruising under sail would ordinarily require no use of fuel.In view of this, the vessel would have a wide range of operation. Also,the form embodied in the hu1 of the vessel makes it possible to locatefuel tanks, water tanks, andmotors below the water level.

It is an object of my invention to provide a vessel suitable foroperation in all kinds of weather, either under sail or motor power, at

speeds such as indicated in the foregoing, this.

vessel having a, hull of novel form, making it suitable for use eitheras a sail boat or power boat. It is an object of the invention toprovide in a' vessel of the class described a hull having [adisplacement keel merging through curved surfaces with concave bottomportions leading to chines which are of a characteristic form andcontribute to the accomplishment of the results forming part of theobjectives of the present invention,

A further object of the invention is to provide a hull capable ofgreater speed through the water than ordinarydisplacement type of hullsof equivalent size, wherein the lines from bow to stem are relativelystraight and the hollow; body sections between the keeland thechinesflareso formed;

Its ordi that they will carrytrapped airunder the vessel fora distancemore than 50% of the water length thereof. 7

It is an object of the invention .to provide ahull of the type describedwhich,.'as the result of a combination of curves and nearly straightbuttook lines, is considerably faster than one and one half times thesquare root of the water line length,"whichiisithe accepted maximumspeed in nautical miles per hour for adisplacement type hull;

A further object of the invention is to provide a hull, the speed. ofwhich under sail isenhanced by the boat riding on her own bow wave whenheeled over under sail, thereby decreasing the "wetted surface byentrapping air in the space supplemented also. if desired by running theexespecially provided between the chines and the underpower operation awetted surface decreased I by the entrapment of air from the bow wave,

haustfrom the 'motors, aide'dby blowers, so that they will pass into theconcaveareas under water, which concave areas will retain the .air untilit reaches the after part of the hull where it will help nullify suctionand stem quarter wave for-- mation."

A further object of the invention is to provide a hull which,.due to theslight curvature of selected buttocklineswill not squat when propelledforwardly.

Further objects tion will be-brought out in the following part of thespecification. I

Referring to the drawings which are for illustrative purposes only;

Fig. 1 is an elevational view of a vessel having a hull embodying myinvention.

Fig. 2-is a schematic plan view showing the body outline of the hulldisclosed in Fig. 1'.

Fig. 3 is a-sectional view taken as indicated by the .line 3--3 ofFig.1.

Fig. 4 is a sectional view on the-plane indicated by the. line 4-4 ofFig. 1.

by the. line '5--5 of Fig. 1. t

Fig. 6, is a sectional view taken as indicated by the line 6--6 of Fig.-1.

Fig. '7 is a sectional view, to reduced scale, taken on a vertical.plane represented by the line 5' of Fig. 2. F

The boat shown in Fig. l comprisesa hull Ill and'a superstruetureshownas rigging ll includmg a mast l2 and sails l3. In Fig.1 a keel His showm.Inflthis description the .l eel' M will. be

and advantages of the inven- Fig. 5 is a sectional view taken asindicated I regarded as a part of the hull l0, and in keeping therewith,the upper portion of 'the hull 10, from which the keel I4 downwardlyprojects, will be referred to as the body portion l5 of the hull In.

The body portion i5 of the hull l0 comprises side walls l6 which meet atthe prow I! above the water line of the vessel, diverge rearwardly to amaximum width at substantially the midsection of the body l5, and thenconverge toward the stem. The side walls It each have a lower edge I8.These lower edges I8 have their front ends l9 starting above the Waterline and sloping downward so as to pass below the water line amidshipsof the vessel, as shown in Fig. 1. I have referred to the keel M as aflotation keel for the reason that it is characterized by its capacityto float the entire weight of the vessel so that the body portion [5 ofthe hull I0 is substantially entirely above the water line 20. keepingtherewith, I have made the keel M of such volume that its displacementis substantially equal to the displacement of the entire vessel equippedand carrying its normal crew. The prow end 2| of the keel I4 isrelatively sharp, as shown in Fig. 6, so that it will have acceptablewater cleavage, but, as shown in- Figs. 5 and 4, the width of the keelI4 is broadened or widened as its upward extension is completed. Then,as the keel progresses rearward through'the vertical plane indicated bythe line 33, it is tapered ofi, as shown in Fig. 3, so that when theedge 22, Fig. 1, is reached, the keel will have a width considerablyless than the diameter of the propeller which operates in a recess 23forming' an opening between the edge 22 and therudder 24 which is hingedthereto. v

Amidships of the hull In the keel is of such width that a chamber 25 isprovided, the upper portion of this chamber 25 being of ample size toreceive the combustion engin 26 which drives the propeller 21'. As shownin Fig. 4, the keel M has side Walls 21, the lower portions 28 of whichare distinctly upright in position, or, in other Words, are verticallydisposed. By this descriptive wording we mean that the lower portions 28of the side walls 21 are near vertical as distinguished from the upperportions 29 of the side walls which are near horizontal so as to formbottom or bilge walls below the body portion [5 of the hull 10. Thelateral edge portions 30 of the keel side walls 21 are bent downwardlyslightly from a horizontal plane so as to meet the lower edges of thebody side walls [6 in a manner to form chines 3|, the bow portions ofwhich lie above the water line, and the amidships portions of whichproject below the water line when the hull is riding level as shown inFig. 1. The stem portions of the chines 3| -lie substan: tially at thewater line, or drop below whenthe vessel is propelled forward atreasonable speed under motor power. In the preferred form ofconstruction, the chines begin near the stem and extend to or nearthetransom, the length of the chines being such that concavities orinverted channels 33 are formed lengthwise of the vessel and inwardly ofthe chines 3|, of such length that the concavities will receive air atthe front ends thereof during forward-motion of the vessel under load,and relatively carry this air under the side portions of the hull bodyIE to the stern and discharge the air at the after part of the hull sothat it will break or partially break the ordinarily encountered sternsuction and diminish stern quarter wave formation. Although the 'keel l4has the displacement characteristics hereinabove described, itsslenderness is such that the buttock lines of the keel portion of thehull have small curvature,'and as the result of the combination oftransverse curves and nearly straightbuttock lines, the ship is not onlyfast under sail power, but also exceptionally fast when under mechanicalpropulsion.

In Figs. 2 and 4 the line 5''5' indicates a vertical plane parallel tothe vertical median plane a-a of the hull. The plane 5' 5 is positioneda distance x from the median plane aa,' which is substantially one-halfthe greatest distance 1/ from the median plane a-ct to the chine. Thisdistance a: is substantially one-fourth of the V greatest width of theunderwater portion of the hull. In keeping with the relation of thisdimension at to the width of the wetted or underwater portion-of thehull, I have referred to the area q of the hull between the plane 5-5'and the portion c of the chine lying distally as the outer quarter ofthe hull. This outer quarter q is duplicated on the left side ofthe hullas indicated at q in Fig. 4.

Between the plane 5'-.-5' of Fig. 2 and the most distal part of thechine portion 0, I have shown buttock lines 6, "l, 8, and 9. 'As viewedfrom above, these buttock lines appear straight. An important feature ofthe invention is that these buttock lines when viewed from the side havea curvature ofless than one inch in ten feet from substantially themiddle section of the hull to the after ends of the individual buttocklines. The forward portions of the buttock lines may be of slightlygreater curvature than this. In Fig. 7, the lower line 5 of the sectionon line 55 comprises the buttock line at the medial limit of the outerquarter q and has the greatest curvature of any of the buttock lines ofthe outer quarter section. It will be noted that the after portion 5athereof is nearly straight, having a curvature of not greater than oneinch in ten feet; whereas, the forward portion 5b has slightly greatercurvature.

This desired effect is enhanced by the boat riding on her own bow wavewhen she is heeled over under sail, at which time the wetted surface isdecreased by the trapping of air between the depressed chine and thekeel. Th spacing and depth of the chines 3| make possible decreasin ofthe external metal ballasts, 35 to a minimum.

As indicated in Fig. 1, fuel tanks 31 may be disposed in the lower partof the chamber 25 of the keel portion l4, and as indicated at 38, awater tank may be located in th forward portion of the chamber 25, belowthe water line.

I claim as my invention:

water line; and a flotation keel having a displacement substantiallyequal to the weight of the vessel disposed centrally below said body,said keel having a vertical depth at least as great as the depth of saidbody, and having side walls, the

lower central portions of which are substantially vertically disposedand the upper portions of which curve outwardly to meet the lower edgesof said body side walls in, a manner to form chines,

the front ends of which are disposed above they water line of the vesseland the intermediate". portions of which chines lie -closeto the waterwhere they meet said body-sidewalls so that inverted longitudinalchannels are thereby formed under saidbody to trap-air during forwardmotion of the vessel andguide the air'toward the stern. of the vessel,said keel side walls being so spaced that the intermediate portionsthereof will define a chamber of a size to receive a motor to power thevessel.

2. In a hull for a sail and power vessel of the character described, thecombination of: a body having side walls extending from the bow portionto the stern portion thereof, the bow ends of the lower edges of saidside walls starting at a point above the water line of the vessel andsloping downward and rearward so as to pass below said waterline; and aflotation keel having a displacement substantially equal to the weightof the vessel disposed centrally below said body, said keel having avertical depth at least as great as the depth of said body, and havingside walls, lower portions of which are substantially verticallydisposed and the upper portions of which curve outwardly to meet thelower edges of said body side walls in a manner to form chines, thefront ends of which are disposed above the water line of the vessel andthe intermediate portions of which chines lie close to the water line,the lateral extremities of the central portions of said keel side wallsbeing bent downward where they meet said body side walls so thatinverted longi tudinal channels are thereby formed under said line, thelateral extremities ofthe middle portions of said keel side .walls beingbent downward body to trap air during forward motion of the vessel andguide the air toward the stern of the vessel and the forward ends of theside portions of said keel side walls rising above the water line of thevessel and meeting the bow portions of said body side walls.

3. In a hull for a sail and power Vessel of the character described, thecombination of: a body having side walls extending from the bow portionto the stern portion thereof, the bow ends of the lower edges of saidside walls starting at apoint above the water line of the vessel andsloping downward and rearward so as to pass below said water line; and aflotation keel having a displacement substantially equal to the weightof the vessel disposed centrally below said body, said keel having sidewalls, lower portions of which are substantially vertically disposed andthe upper portions of which curve outwardly to meet the lower edges ofsaid body sidekwalls'in a manner to form chines, the front ends of whichare disposed above the water line of the vessel and the intermediateportions of which chines lie close to the water line, lateralextremities of said keel side walls being bent downward where they meetsaid body side walls so that inverted longitudinal channels are therebyformed under said body to trap air during forward motion of the vesseland guide the air toward the stern of the vessel, said keel side wallsbeing so spaced that the intermediate portions thereof will define achamber of a size to receive a motor to power the vessel.

4. In a hull for a sail and power vessel of the character described, thecombination of: a body having side walls extending from the bow portionto the stern portion thereof, the bow ends of the lower edges of saidside walls starting at a point above the water line-of the vessel andsloping downward and rearward so asto pass below said water line; and aflotation keel having a displacement substantially equal to the weightof the vessel disposed centrally below-said body, said keel havingsidewalls, the lower centralportlons;

of which'a're substantially vertically disposed and the-upper portionsof which curve outwardly to, meet the lower edges of said body sidewallsain a manner to form chines, the-front ends: of which are disposedabove the water line of the vessel and the intermediate portions ofwhich chines lie close to the water line, lateral extremities of saidkeel side walls being bent downward where they meet said body sidewallsso that inverted longitudinal channels are thereby formed under saidbody to trap air during forward motion of, the vessel and guide the airtoward the stern of the vessel and the forward ends of the side portionsof said keel side walls rising above the water line of the vessel andmeeting the bow portions of said body side walls.

5. In a hull for a sail and power vessel of the character described, thecombination of z a body having side walls extending from the bow'portionto the stern portion thereof and a flotation keel having atdisplacementsubstantially equal to the weight of the vessel disposedcentrally'belowsaid body, said keel having a vertical depth at least asgreat as the depth of said body, and having side walls, the lowercentral portions of which are substantially vertically disposed and theupper portions of which curve outwardly to meet the lower edges of saidbody side walls in a manner to form chines, the front ends of which aredisposed above the water line of the vessel and the intermediateportions of which chines lie close to the water line, the lateralextremities of the central portions of said keel side walls'being bentdownward where they meet said body side walls so that invertedlongitudinal channels are thereby formed under said body to trap airduring forward motion of the vessel and guide the air toward the sternof the vessel.

6. In a hull for a sail and power vessel of the character described, thecombination of: a body having side walls extending from the bow portionto the stern portion thereof; and a flotation ,keel having adisplacement substantially equal to the weight of the vessel disposedcentrally below said body, said keel having side walls, the lowercentral portions of which are substantially vertically disposed and theupper portions of which curve outwardly to meet thelower edges of saidbody side walls in a manner to form chines, the front ends of whichchines are'disposed above the water line of the vessel, and theintermediate portions of which chines lie close to the water line, theupper portions of said keel side walls projecting downwardly along theline of meeting of said body side walls and said keel side walls so thatinverted longitudinal channels are thereby formed under the centralportion of said body to trap air during forward motion of the vessel andguide the air toward the stern of the vessel. 7

7; In a hull for a sail and power vessel of the character described, thecombination of a body having side walls extending from the bow portion.

to the stern portion thereof; and a flotation keel having a displacementsubstantially equal to the weight of the vessel disposed centrally belowsaid body, said keel having a vertical depth at least as great as thedepth of said body, and having side walls, the lower central portions ofwhich are substantially vertically disposed and the upper portions ofwhich curve outwardly to form outer quarters, the buttock lines of whichhave an average curve of not greater than about one inch in ten feet,the lateral extremes of said upper portions meeting the lower edges 01'said body side walls in'a manner to form chines, the front ends of whichchines are disposed above the water line of the vessel and theintermediate portions of which chines lie close to the water line andproject downwardly along the line of meeting of the intermediateportions of said body side walls and the intermediate portions of saidkeel side walls so that inverted longitudinal channels are therebyformed under said body to trap air during forward 'motion of the vesseland guide the air toward the stern of the vessel.

ARCHIE A. STEELE.

